Currently, because the industrial waste water generated in some professional domains has many shortcomings such as large amount of discharge and high density of pollutant, which is causing more and more serious pollution to the water environment and destroying the ecological equilibrium of all the world, it both seriously effects human living environment and hinders the development of these professional domains. Because the problem of sewage treatment and the ecological environmental protection is considered more and more important in various professional domains, massive persons and money have been used in the topic research, and many research results have been achieved. The pollutant in waste water mainly includes: biologically decomposable organic matter, volatile organic matter, uneasily decomposing organic matter, toxic metal, suspended solid matter, nutrient salt (nitrogen and phosphorus), pathogenesis microorganism and parasitic zoology and botany or the like. The standard of the industrial water pollutant discharge according to the current national provisions is to mainly define biochemical oxygen demand (BOD5), chemical oxygen demand (COD), chromaticity, PH value, suspension, ammonia and nitrogen, sulfide, hexavalent chromium, copper, phenyl amines, chlorine dioxide or the like. So it is the main object of sewage treatment to degenerate, reduce and control the density and amount of the above ones to achieve and even lower than the standard of the pollutant discharge according to the national provisions.
Currently, general treatment methods in industrial waste water and living sewage include physical treatment methods, chemical treatment methods and biological treatment methods. In physical treatment methods, organic impurities such as suspension, floating matter and fine fiber are removed by bar screen and strainer, adjustment, precipitation, gas floating and filter membrane. In chemical treatment methods, by placing various medicaments in the neutralization tank or the response pond, in the way of neutralization, coagulation, electrolysis, oxidation, adsorption, disinfection or the like, PH value, color waste matter, colloid suspension, BOD biochemical oxygen demand, COD chemical oxygen demand, LAS linear chain alkyl benzene sulfonate, tiny suspension, macromolecule organic matter and bacterium are processed. Biological treatment methods mainly include anaerobic biological process and aerobic biological process, wherein: in anaerobic biological process BOD, COD, color waste matter, NH3—N and phosphorus are mainly processed by upstream anaerobic sludge bed, anaerobic attached film expanded bed, anaerobic fluidized bed and hydrolysis acidification or the like; in aerobic biological process BOD, COD, color waste matter, NH3—N and phosphorus are mainly processed by recycled activated sludge treatment, adsorption regeneration oxidation method and biological contact oxidation method.
Generally, conventional sewage treatment devices or systems adopt a sole one of physical treatment methods, chemical treatment methods and biological treatment methods. Though they have effect on improving some standards of water quality, in fact they have limitation and total processing results are not desirable. Moreover the expense of the infrastructure and device of these processing methods in earlier period is expensive, and the cost of operation is very high because a large quantity of medicaments and chemical additives are frequently placed in operation. In addition, during all the period of processing the sewage other pollutant, particularly massive sludge is generated and discharged. While some sewage treatment devices have functions of concentrating, drying and grinding sludge, at last the pollutant must be discharged to the outside, which will be a new pollution source regardless of falling to rubbish site or burying deeply in the earth. Therefore, current sewage treatment methods can not indeed realize the object of environmental protection.